The increasing miniaturization of opto-electronic components and special requirements, particularly with regard to the threshold current and the radiation quality, lead to the radiation-emitting active area of such components frequently being constructed to be relatively small. On the other hand, it is known that a relatively small active area produces increased sensitivity of the component to electrostatic discharges (ESD). Such ESD voltage pulses can impair the operation of an opto-electronic component or even destroy it.
From U.S. Pat. No. 6,185,240 B1, a vertical cavity surface emitting laser (VCSEL) is known which contains a protective diode integrated monolithically on the semiconductor substrate for increasing its ESD resistance. This protective diode is connected in antiparallel with the VCSEL by means of a multi-stage etching process and suitable running of the contact metallizations and in this manner protects the VCSEL from ESD voltage pulses which occur in the reverse direction of the pn junction of the VCSEL.
A further radiation-emitting semiconductor component with improved ESD immunity is known from DE 199 45 134 A1. In this component, a monolithically integrated protective diode is implemented by providing a part of the pn junction with a Schottky contact. The part-section provided with the Schottky contact is connected in parallel with the light-emitting section and has the same forward direction. Due to a steeper current/voltage characteristic, the current preferably flows through the protective-diode section at high voltages in the forward direction. In this manner, this component is protected against ESD voltage pulses in the forward direction.